Assignment 6: GloFish, A Genetically-Modified Organism
Overview and History: GloFish are a type of zebrafish that have been genetically modified to "fluoresce"--hence their name--which is actually patented and trademarked by Yorktown Technologies, the Texas-based company that funded the creation of this genetically-modified organism in 1999. GloFish were originally created by scientist Zhiyuan Gong at the National University of Singapore to monitor pollution levels in aquatic bodies. The idea behind Gong's research and subsequent success was to have a fish that would "light up" in the presence of environmental toxins. Thus, these fish could be released into various bodies of water (such as those used by fisheries or electric and oil companies), and would essentially act as "gauges," relaying information about the "health" of the water. This concept is not unlike the canary in the coal mine, as the fish were to serve as a "danger" indicator. He chose zebrafish, as they are inexpensive, easy-to-breed, and equipped with a genome that is easy enough to modify. Genetic Modifications of the Zebrafish to Create GloFish: GloFish are essentially zebrafish--native to India--that have the addition of a jellyfish gene called GFP (green fluorescent protein) that codes for green fluorescence. Jellyfish produce this gene naturally, and Gong and his group of scientists were able to integrate this gene into the genome of zebrafish by inserting the jellyfish's green fluorescecent protein into the zebrafish embryo, which allows for integration into the zebrafish genome. What was ultimately created is a constantly-flourescent fish, which was only the first stage in the creation of selectively-fluoresceing fish that would only "illuminate" in the presence of toxins. Thus, the next step after the constantly-fluorescing green fish was to add to the zebrafish genome a variety of colors that would only appear in the presence of specific toxins. Pink-coding proteins from coral were added to the zebrafish embryos, as well as orange and blue proteins from various tropical marine life. While the idea was for the fish to be pollution monitors, this never quite occurred, as they quickly gained mainstream praise and appeal, which lead Yorktown Technologies to scrap the "bio indicator" purpose of the fish, and instead focus on commodifying GloFish as household "pets." Yorktown capitalized on these neon fish by marketing them as "the first genetically-modified organism" available for sale to the public. Thus, the experiments to create a GloFish that only lit pink in the presence of sewage spill, for instance, were terminated, and Yorktown ordered that all genetic modifications going forward would be in the name of aesthetics. GloFish became available in pet stores around the United States in 2001, and have been modified since to express constant neon hues of red, purple, pink, dark green and other exotic colors. All of these color combinations stem from the implant of a color protein coding gene (usually from jellyfish or sea coral) into the zebrafish embryo, and from there on out, the fish are able to reproduce their own fluorescent-hued offspring by naturally means (general reproduction, passing along traits from parent to offspring). While other pollution-indicator fish have been created via genetic modifications, GloFish are a particular instance of a science endeavor gone mainstream and capitalist, with the prospect of large-scale public consumption trumping the original purpose of the fish as an environmental gauge. This reality has caused the state of California to actually ban the sale of GloFish (they are illegal) because its government believes them to be "trivial," and an example of "greater good gone bad." All other states in the U.S. and myriad other counties sell these fish for mere dollars. Resources: GloFish for Science Sparks JS, Schelly RC, Smith WL, Davis MP, Tchernov D, et al. (2014) The Covert World of Fish Biofluorescence: A Phylogenetically Widespread and Phenotypically Variable Phenomenon. PLoS ONE 9(1): e83259. doi:10.1371/journal.pone.0083259 Star, Barry. QUEST California. 2013 Vick, BM, et al. PubMed: Zebrafish. 2012 Dec;9(4):226-41. doi: 10.1089/zeb.2012.0758.